FGF23 and chronic obstructive pulmonary disease: Our lab has also shown that FGF signaling increases inflammation in several lung diseases; for example, FGF23 levels are upregulated in CF, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis and exerts a pro-inflammatory effect (in combination with TGF-β and cigarette smoke) in the CF and COPD bronchial epithelium.